Through the combination of wireless telephony and mobile computing technologies, digital wireless handsets are now available that can allow users to communicate with others by voice, e-mail, paging, facsimile, etc., and to transmit or receive information through the internet over a wireless network. Manufacturers of internet-capable telephones and personal digital assistants (PDA's) are coordinating with internet web site content providers to develop specialized versions of popular web sites for wireless access and interaction. In almost any location, while stationary or while in motion, consumers can use wireless networks to browse the world-wide web, participate in e-commerce transactions, join others through interactive game software, or communicate with others by voice or by other means through transmission of data.
Wireless cellular networks operate by establishing a communications link over radio waves between a mobile transmitter/receiver and a network transmitter/receiver located in the general vicinity of the mobile transmitter/receiver. Network transmitter/receivers each provide coverage for a limited geographical region, or cell, and are usually located near the center of the respective region on a cell tower. As a mobile transmitter/receiver is moved across different regions during a wireless communication, e.g., in an automobile, the call is transferred from one cell tower to the next.
For wireless communications, a bottleneck occurs during busy periods that can slow down communications because there are a limited number of radio links, or access points, into the wireless network. During the course of a day, the volume of subscribers requesting cellular service at cells in certain locations may overload the cell and strain capacity. For example, cells that are located near high traffic roadways that lead to a downtown city may be extremely busy during the morning and evening rush hours. Cells that are located near shopping malls in suburban areas may become congested during the weekend. Some cells may become overloaded during special events or holidays. Conversely, other cells may be relatively empty or unoccupied during certain times of the day. For example, cell sites in a downtown city may be unoccupied during the weekend, while many suburban cell sites are crowded.
When a cell site is operating at full capacity, the mobile transmitters/receivers may have to wait before obtaining access for communications. While a transmission delay may not be significant for an e-mail communication or a file transfer, the delay is probably not acceptable for voice-over-IP telephony or other time-sensitive communications. Under the current cellular service systems, with airtime priced either according to “peak” and “nonpeak” time or a fixed rate with a number of minutes allotted, there is no incentive for subscribers to refrain from accessing the wireless network at a busy cell site, as opposed to waiting until the subscriber is located near an uncrowded cell site.